title: False-positive iodine-131 whole-body scan findings in patients with differentiated thyroid carcinoma: report of 11 cases and review of the literature.
abstract: BACKGROUND
  Iodine-131 (I-131) whole-body scan (WBS) plays an important role in the management of patients with differentiated thyroid carcinoma (DTC), to detect normal thyroid remnants and recurrent or metastatic disease. A focus of I-131 accumulation outside the thyroid bed and the areas of physiological uptake is strongly suggestive of a distant functioning metastasis. However, many false-positive I-131 WBS findings have been reported in the literature.
  
  
  METHODS
  We describe a series of 11 personal cases of patients with DTC, collected from 1992 to 2011, in whom diagnostic or post-treatment WBS showed false-positive retention of I-131 in various locations.
  
  
  CONCLUSIONS
  False-positive accumulations of I-131 on WBS may be classified according to the underlying pathophysiological mechanisms: external and internal contaminations by body secretions, ectopic normal thyroid and gastric tissues, inflammatory and infectious diseases, benign and malignant tumors, cysts and effusions of serous cavities, thymic uptake, and other non classified causes.
  
  
  CONCLUSIONS
  Clinicians must be aware of possible false-positive findings to avoid misinterpretations of the I-131 WBS, which could lead to inappropriate treatments.
authors.affiliation: Service d'endocrinologie, faculté de médecine, université Angers, centre hospitalier universitaire, 49933 Angers, France.
authors.forename: Leckzinscka
authors.initials: L
authors.lastname: Buton
authors.forename: Olivier
authors.initials: O
authors.lastname: Morel
authors.forename: Patricia
authors.initials: P
authors.lastname: Gault
authors.forename: Frédéric
authors.initials: F
authors.lastname: Illouz
authors.forename: Patrice
authors.initials: P
authors.lastname: Rodien
authors.forename: Vincent
authors.initials: V
authors.lastname: Rohmer
mesh_terms: D000328:Adult; D000368:Aged; D002291:Carcinoma, Papillary / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000601:surgery; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000601:surgery; D051598:Whole Body Imaging / Q000379:methods* / Q000706:statistics & numerical data
chemical_list: D007457:Iodine Radioisotopes